Daniel Loic Pouliquen ^1,2,3,4,5* Susana P. Gaudêncio ^6,7,8,9*

• ¹ Institut National de la Santé et de la Recherche Médicale (INSERM), Paris, Île-de-France, France
• ² Centre National de la Recherche Scientifique (CNRS), Paris, France
• ³ Centre de recherche en cancérologie et immunologie intégrée Nantes (CRCI2Na), Nantes, Pays de la Loire, France
• ⁴ Nantes Université, Nantes, France
• ⁵ Université d'Angers, Angers, Pays de la Loire, France
• ⁶ Associate Laboratory i4HB - Institute for Health and Bioeconomy, University of Lisbon, Lisbon, Lisbon, Portugal
• ⁷ Nova School of Science and Technology, Faculty of Science and Technology, New University of Lisboa, Caparica, Portugal
• ⁸ UCIBIO-Applied Molecular Biosciences Unit, Chemistry Dept, Blue Biotechnology and Biomedicine Lab., Lisboa, Portugal
• ⁹ NOVA University of Lisbon, Lisbon, Lisboa, Portugal

Marine ecosystems account for more than 80% of the planet's biodiversity [1]. Despite their immense potential for health, they have been studied far less than terrestrial ecosystems for the discovery of innovative drugs. Nonetheless, fifteen marine-derived drugs have already been approved for commercialization (https://www.marinepharmacology.org/approved), including eight8 anticancer drugs. This vast marine biodiversity, along with the intricate and unique adaptations that enables survival in challenging physical environments, serves as a rich source of inspiration for scientists, driving innovative concepts and biotechnological developments. Over the past decades, several exciting areas of research have emerged and benefited from translational exchanges between marine sciences and oncology. Some examples include the "One World -One Health Concept" for the study of the impact of human activities on marine species oncogenesis, transmissible cancers, and tumor suppressor mechanisms [2]. The deep-sea environment offers a vast reservoir of microorganisms, fungi, and invertebrates, complemented by algae and phytoplankton thriving in upper sea levels. Together, these organisms produce an extensive variety of primary and secondary metabolites, many of which exhibit potential anti-cancer and / or immunomodulatory properties [3]. Beyond small molecules, marine organisms also synthesize a diversity of macromolecules with unique biological, physicochemical and structural properties, holding potential for by-products valorization, offering positive outcomes for both marine science and oncology [4]. The articles within this research topic explores various aspects of these compelling translational connections (https://www.frontiersin.org/research-topics/58861/the-blue-frontier-cancer-research-meets-the-diversity-of-marine-chemistry-and-biology-new-challenges-and-prospects/articles).Aligned with the "One Health" principles, previous investigations on marine species populations affected by cancer allowed to identifiedy transmissible cancers in bivalves [5], while providing insights into the pathogenesis of some common cancers between fishes and humans [6]. Building on multiyear, collaborative studies on marine mammal cancers [7], an international team recently investigated fibropapillomatosis in green sea turtles (Whilde et al.